The science Behind the Supplement

The biological relationship between diet, lifestyle and mental health

Let’s start with a simple analogy – if you put petrol into a diesel car, how well do you think that car will perform?
Similar logic applies to the brain.

Research now presents diet and lifestyle as modifiable risk factors for mental illness [1]. That phrase is very important, while there are various factors that affect our mental health which we cannot control – we can influence how our body performs both positively and negatively through our lifestyle choices.

The main focus of these studies so far has focused on the influence of diet on monoamine neurotransmitter production & synthesis [2], as well as the effects of inflammation, free radicals & oxidative stress in relation to mental illness [1].

The argument isn’t “the more you have, the better you will feel” or that “this cures depression”. It’s about reducing the variables and providing what should already be in place through healthy lifestyle habits so that our body and brain are able to function to the best of their ability – rather than running on fumes.

As such, modifying that risk factor.

You’ve most likely heard of most of the monoamine family:
serotonin, dopamine, epinephrine, norepinephrine and acetylcholine.

The impact that monoamine imbalance has on mental health is not up for debate in the medical world – the key function of most common medical interventions (antidepressants) is to alleviate depressive symptoms through greater monoamine availability [4].

It has now though been universally accepted that certain nutrients represent as precursors to these important neurotransmitters and by altering the diet, we can also alter neurotransmitter synthesis within the body [3], and also influence their performance [4].

As an example:
Serotonin is collectively known as the neurotransmitter that makes us happy and, biologically, people who suffer from depression are shown to suffer from reduced serotonin uptake [5]. Serotonin though needs to be synthesised from the amino acid tryptophan which is obtained only through a healthy and balanced diet, our body cannot create serotonin on its own.

If it’s common in hospitality to be working in high-stress environments, with higher rates of smoking & drinking, lower rates of exercise, limited access to natural sources of vitamin D & our main meal each day is being constructed based on cost rather than nutritional value..

Would it be a surprise if our monoaminergic system was not running at optimal capacity?

This is where things get interesting, to convert tryptophan and absorb serotonin effectively your body then requires certain levels of magnesium [6], vitamin d and b vitamins [7]. you may have optimal levels of tryptophan, but without these, your body will not convert tryptophan into serotonin.

Things get more complicated for hospitality workers.
Acute stress will increase magnesium excretion [6], while long term stress will deplete our B vitamin levels [8]. Stress also contributes to an increase in inflammation and the release of a compound called IDO, which converts tryptophan into kynurenine rather than making it available to become serotonin. Put simply, the more stressful situations we have, the less serotonin we likely produce [5].

Hospitality then has the highest rate of smokers of any U.K industry and it’s shown that smoking greatly reduces serum magnesium levels [6]. Regular alcohol consumption is shown to further increase urinary magnesium loss 2-3 fold [6] and also being a major cause of loss of the B vitamins [8]

Aerobic exercise is shown to increase the availability of tryptophan within the body, as well as increasing availability and concentrations of serotonin transporters and receptors [3].

similar patterns emerge with the other monoamines, interupting other aspects of our brain’s function affecting motivation, pleasure, concentration, learning, anxiety and more.

If we’re losing just as many nutrients as we’re obtaining through our diet, how can we expect optimal brain performance?

The Destructive Cycle

We’ve all reached for a drink or a cigarette to destress after a bad day or a tough customer. But another worrying finding is that this relationship between lifestyle and mental health appears to be bidirectional [3]. Put simply, lifestyle choices will influence our mental health & then our mental health will influence our lifestyle choices. Creating this destructive cycle.


It’s often easier to accept that our psychological health is linked to stressful experiences rather than determined, to a degree, by our immune system. It’s important though to understand that when we encounter stress, grief or trauma, it does actually induce certain internal biochemical bodily responses – notably inflammation [5].

Inflammation is a double-edged sword, it’s equipped to destroy threats to the body, but is also equally capable of damaging healthy tissue [9].

It’s now been suggested that chronic low-grade inflammation, resulting in an elevation of pro-inflammatory cytokines and acute-phase proteins, is implicated in the development of depression [5]. Causes for this inflammation are various but can include psychological stress, smoking, obesity, lack of sleep and of particular relevance – poor diet [1].

This inflammatory process will produce something called free radicals within the body to fight the ‘threat’. Normally healthy electrons will exist in pairs, free radicals though have an odd number and will steal an electron from another molecule – which then, in turn, becomes a free radical itself [10].

Antioxidants, on the other hand, have the ability to donate an electron to a free radical without themselves becoming a free radical [10]. As long as we have a balance between free radicals & antioxidants we’re fine – when we don’t, we encounter oxidative stress. studies now show that  decreased antioxidant status & elevated oxidative stress is found in depressed populations [1,3,4].

Without antioxidants to limit the multiplication of these free radicals, it can set off a chain reaction [10] which can result in neuronal damage (cells in the brain) and interference with cell junctions – leading to a decline in cognitive function [3]. As the body also sees this oxidative stress as harmful, the body will then release pro-inflammatory cytokines to further stimulate inflammation and begin the body’s defence against the threat.

unfortunately, these cytokines can also cause of depression and anxiety [11] and interfere with monoamine neurotransmitters [5]. In fact, people suffering from clinical depression are shown to have 40-50% higher levels of pro-inflammatory cytokines [5]

The longer this cycle  of inflammation and oxidative stress continues – the more at risk we are of developing depressive symptoms.

Unfortunately the hospitality lifestyle can cause some issues here;

  • nutrient deficiencies limit our body’s ability to overcome these states
  • A western diet high in red meats and processed meats, refined carbohydrates and other processed foods is associated with increased inflammatory markers and cytokines [11].
  • Stress may stimulate the pro-inflammatory network while also lowering levels of anti-inflammatory compounds [11]
  • Acute sleep deprivation impairs immune functioning and produces high levels of cytokines [11]
  • Alcohol-mediated activation of inflammatory signals can increase levels of cytokines [9]
  • cigarette smoke contains thousands of chemicals, including free radicals, tars and other substances that induce inflammatory responses in bodily tissues and increase levels of oxidative stress [11]

While lifestyle can negatively affect both inflammation and oxidative stress, it can also help to combat it. Magnesium availability appears to affect the occurrence of oxidative stress [6] and vitamin D supplementation is shown to greatly reduce levels of cytokines [11]. Exercise as well promotes healthy brain condition by reducing inflammation and suppressing oxidative stress [3]. Consuming adequate antioxidants through our diet can also help to avoid the oxidative state in the first place.

If it’s common in the hospitality industry to be working in high-stress environments, with higher rates of smoking and drinking, lower rates of exercise, infrequent sleep,  limited access to natural sources of Vitamin D and our main meal each day is being constructed on cost rather than nutritional value..

would it really be a surprise if inflammation and oxidative stress played a role in elevated rates of common mental health problems in the hospitality industry?

The ‘SMILES’ Trial [12]

The SMILES trial examined the therapeutic impact of dietary changes on existing mental illnesses  and was published in 2017- it was an incredibly important study in this field. ‘SMILES’ lasted 12-weeks and all participants had known depressive disorders – Of the participants, 68.7% were already on antidepressant medication and 44.8% were already receiving Psychological therapy, most likely cognitive behavioural therapy (CBT).

Half of the participants were given nutritional guidance throughout the trial, while the other half received social support and coaching – all participants received the same amount of sessions and same level of support.

At 12 weeks there was a significantly greater improvement in depression scores within the dietary group compared to the social support group. Participants did not change their energy intake or body weight during the trial which suggests that these improvements were not related to weight status or BMI.

Furthermore, there was a far greater level of remission in the dietary support group 32.3% compared to just 8% in the social support group.

The results of the SMILES trial suggest that nutritional intervention may be a useful strategy for addressing depressive disorders in both the general population and in clinical settings. Justifying, we think, Hospro’s importance in this space.


1 – Marx, W., Moseley, G., Berk, M., & Jacka, F. (2017). Nutritional psychiatry: the present state of the evidence. Proceedings of the Nutrition Society, 76(4), 427–436. Cambridge University Press.

2 – Christensen, L. (1996). Diet–Behavior Relationships: Focus on Depression.

3 – Farooqui, T., & Farooqui, A. A. (2015). Diet and exercise in cognitive function and neurological diseases.

4 – Lopresti, A. L., Hood, S. D., & Drummond, P. D. (2013). A review of lifestyle factors that contribute to important pathways associated with major depression: Diet, sleep and exercise. Journal of Affective Disorders, 148(1), 12–27.

5 – Watts, M. (2014). Nutrition and Mental Health A Handbook.

6 – Turner, R. J., & Vink, R. (2011). Magnesium in the Central Nervous System. New Perspectives in Magnesium Research.

7 – Young, L. M., Pipingas, A., White, D. J., Gauci, S., & Scholey, A. (2019). A Systematic Review and Meta-Analysis of B Vitamin Supplementation on Depressive Symptoms, Anxiety, and Stress: Effects on Healthy and ‘At-Risk’ Individuals. Nutrients, 11(9).

8 – Lee, J. (2013). Brain 2.0 – Super-charge Your Brain with Mind-boosting Nootropic Supplements and Drugs.

9 – Wang, H. J. (2010). Alcohol, inflammation, and gut-liver-brain interactions in tissue damage and disease development. World Journal of Gastroenterology, 16(11).

10 – Lee, J. (2014). N-acetylcysteine – Boost glutathione, heal your liver and soothe your brain with the power of Nac.

11 – Berk, M., Williams, L. J., Jacka, F. N., O’Neil, A., Pasco, J. A., Moylan, S., … Maes, M. (2013). So depression is an inflammatory disease, but where does the inflammation come from? BMC Medicine, 11(1).

12 – Jacka, F. N., O’Neil, A., Opie, R., Itsiopoulos, C., Cotton, S., Mohebbi, M., … Berk, M. (2017). A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial). BMC Medicine, 15(1).